KEY TECHNICAL ISSUES AND RESEARCH WORK IN YALONG …

Chen Yunhua

PhD, General ManagerYalong River Hydropower Development Company, Ltd.

KEY TECHNICAL ISSUES AND RESEARCH WORK IN YALONG RIVER

HYDROPOWER DEVELOPMENT

35th IAHR World Congress

HIGHLIGHTSI. HYDROPOWER RESOURCES OF THE YALONG RIVER

II. DEVELOPMENT STRATEGY AND PROGRESS

V. PROGRESS IN RESOLUTION OF THE KEY ISSUES

IV. RESEARCH WORK

III. KEY TECHNICAL ISSUES

VI. CONCLUSION AND EXPECTATIONS

HIGHLIGHTSI. HYDROPOWER RESOURCES OF THE YALONG RIVER



IV. RESEARCH WORK



I. HYDROPOWER RESOURCESOF THE YALONG RIVER

I. HYDROPOWER RESOURCES OF THE YALONG

Originates in Qinghai Province, passes through Sichuan, and joins the Jinsha River.

River length: 1,571km

Natural head: 3,830m

Catchment area: 136,000km2

Annual runoff: 61 billion m3

呷衣寺

Map of the Yalong River Basin

21 cascade projects planned

Technical developable capacity: 30,000MW, 24% of Sichuan or 5% of China

Technical developable annual generation:150TWh

Ranking 3rd among China’s 13 hydropower bases


Planned Cascade Stations along the Yalong River

The Upper Reach

Upstream of Lianghekou, 688km9 cascade projects, 2,500MW


Longitudinal Section of the Cascade Stations along the Yalong River

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The Middle Reach

Lianghekou to Kala,385km7 cascade projects, 11,505MWLianghekou has a multi-year regulating reservoir


Lianghekou

Kala

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The Lower Reach

Kala to confluence, 412km5 cascade projects,14,700MWJinping-I has a yearly-regulating reservoir


Jinping-I

Ertan

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Lianghekou

Jinping-I

Ertan

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In the Middle & Lower Reaches large-size projectssmall inundation lossessimplex development purposesubstantial scale advantagesexcellent cascade compensation benefits

When formed, a regulating storage of 14.84 billion m3

When joint operated, multi-year regulating capacity


Lianghekou

Jinping-I Ertan

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Distance(km)


Stage 1Stage 1Before Before 2000:2000:Complete Ertan Hydropower Station to achieve a capacity of 3,300MW

Ertan:Ertan: 3,300MW3,300MW


The ‘4-stage’ Development Strategy

JinpingJinping--I 3,600MWI 3,600MWJinpingJinping--II 4,800MWII 4,800MWGuandiGuandi 2,400MW2,400MWErtan Ertan 3,300MW3,300MWTongzilinTongzilin 600MW600MW

Stage 2Stage 2Before 2015:Before 2015:Complete lower reach stations of 11,400MW to raise the total capacity up to 14,700MW



LianghekouLianghekou 3,000MW3,000MW…………YangfanggouYangfanggou 1,500MW1,500MWKala Kala 980MW980MW

Stage 3Stage 3Before 2020Before 2020：：Add 8,000MW of new capacity to raise the total capacity up to 23,000MW.



Before 2030Before 2030：：Complete all remaining projects to reach the total capacity of

30,000MWValley development Valley development completecomplete

Stage 4Stage 4



Lower reach: Construction works going on well, with units put into service in succession since 2012

Middle reach: Preparatory works underway

Upper reach: Preliminary works for main projects started


Development Progress



Yalong River Basin lies in steeply cut deep gorges, with complex geological conditions.

JinpingJinping--II World’s highest dam of 305m

JinpingJinping--IIII World’s largest hydraulic tunnel group with great overburden

LianghekouLianghekou Super-tall rockfill dam of 300m

World-classProjects

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11. High dam design theory and methods

2. Stability and treatment of high and steep slopes incomplex geology

3. Safety of the deeply buried, long and large diametertunnel group

4. Real-time control and management of the constructionprocess

5. Optimized joint operation of cascade stations

6. Environmental benefits and engineering measures


Increase in dam height from 200m to 300m makes the structural safety of a dam and its flood discharge capacity disproportionately more demanding

High dam loading and deformation

Properties of aggregate source &

dam concrete

Structural dynamics and anti-seismic

safety

1. High Dam Design Theory & Methods


Spillway dissipation & spray effect

Dam site topographyDam site topography

Excavation of Jinping-I dam foundation and abutment formed steep slopes some 535m in height;

Faults and joints in the left bank made the job more challenging.

2. High Slope Stability and Treatment

535m


Jinping-II

4 headrace tunnels, 2 access tunnels, 1 drainage tunnel

Max. overburden:2,525m

Large overburden, long length, large diameter (13m)

World’s largest hydraulic tunnel group

2,525 m

17 km

Overburden of Long Tunnels thru Jinping Mountains

Overburden of Long Tunnels thru Jinping Mountains

3. Safety of Deep, Long & Large Tunnel Group


Rock burst under high stresses (up to 70MPa)

High-pressure water gushes (e.g. maximum initial inflow at a single point reached an incredible 3.73 m3/s)

Construction ventilation

Fast TBM boring and mucking

Load relief and deformation during excavation of huge powerhouse caverns

Issues Faced in Tunnel Construction


Scattered layout of construction facilities made management and communication rather difficult.

4. Real-time Control of Construction Process


No precedent in China

For such a large basin

Lack of theoretical preparedness and practical experience

Operation modes of the primary cascade stations call for detailed and in-depth studies.

With 21 stations, optimized approach to joint operation management of the stations is imperative.

5. Optimized Joint Operation of Cascade Stations


6. Environmental Benefits and Engineering Measures


Study the impact on the ecology against the benefits of basin development.

Establish quantification methods and criteria for appraisal of environmental impacts.

Mitigate adverse impacts on environment by means of engineering measures.

Impact on the environment is one of the key issues requiring valid and acceptable solutions.

IV. RESEARCH WORK

IV. RESEARCH WORK

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Co-operation with high-end research platforms ensured

substantial resolution of the key issues

Established a research fund with the National Natural Science Foundation of China to finance research forces from across the Nation

Cooperated with China’s best-known universities and research institutes to study the issues

1. High Dam Design Theory and Methods

arch dam realistic working

and behavior simulation

high performance

mass concrete

hydraulics of high-head & large-flow spillway tunnels

arch dam failure mechanism &

safety assessment

spillway dissipation technology for

300m high dams

high rockfill dam deformation analysis

& safety control

Research work in application of fundamental theories and innovative technologies

testing of earth/rock material

under complex loading conditions

IV. RESEARCH WORK

내용Jinping-I

Dam materials and structural study

Seepage properties and control measures

Arch dam mechanics test and stability studySpillway dissipation testDam concrete test Dam foundation reinforcing measures

Lianghekou

IV. RESEARCH WORK

1. High Dam Design Theory and Methods


Dynamic mechanical process for development of high slopes in theYalong Basin, and their engineering adaptability evaluation

Analytical methods for deformation and stability of complex highand steep slopes in China’s South-west

Pre-warning and preventive measures for large slides of high rock slopes triggered by loss of stability

High slope monitoring and warning system to monitor steep slope construction activities

IV. RESEARCH WORK

Theoretical and experimental research in engineering properties of deep-buried rock mass

Development of stress-detecting robots

Forecasting and treatment of high-pressure large-flow underground water and adverse geological conditions

Forecasting and stability analysis of the large headrace tunnels and power house caverns

IV. RESEARCH WORK

3. Safety of Deep, Long & Large Tunnels and Tunnel Group

Comprehensive rock burst prevention system

Geological forecasting & grouting technology for sealing-off high-pressure water

TBM construction and conveyor systems, and long tunnel ventilation technology

Stability study of power house caverns

Based on above work

IV. RESEARCH WORK

3. Safety of Deep, Long & Large Tunnels and Tunnel Group

4. Real-time Control and Managementof Construction Process

IT-aided Construction Management

Real-time control and management of construction process

Fast integration of important data for real-time control of construction process by means of GPS technology

A real-time control system developed to aid management of construction quality and progress

For Jinping-I, a system was developed for automatic controlof dam concrete temperature

IV. RESEARCH WORK

5. Joint Operation of Cascade Stations

Power plant dispatch modes

Joint operation models and methods

Jinping-II transitional process and constraining conditions

Real-time monitoring system of Jinping-I and Guandi spillway dissipation safety

Coupled vibration properties of generator units and their operation methods

IV. RESEARCH WORK

6. Environmental Benefits andEngineering Measures

Study of Environment Benefits and Impact

design of multi-level water intake

structure

Planting technology improved restoration

of the vegetation

environmental impact

assessment

study of fish hatch & release technology

study of standard for ecological flows

IV. RESEARCH WORK


1. High Dam Design and Real-timeConstruction Control

Structural design of Jinping-I mostly finalized

Slit-type bucket adopted for surface & low-level dam outlets to extend the nappe for collision avoidance

Dovetail bucket used for tunnel spillways

simulation experiment

dovetail bucket for tunnel spillway

V. PROGRESS IN RESOLUTION OF KEY ISSUES

For dam concrete, coarse aggregate of quartzitic sandstone and fine aggregate of marble were used.

Dam concrete construction quality has been closely controlled

Aggregate Production System





Key design & construction issues for super-high arch dam basically solved


Excavation and support of Jinping-I high slopes all completed by 2008.

After reservoir filling, monitoring data show that slope deformation is well within the safety range.

anchoring work of left bank slope above El.1,885m



Comprehensive rock burst prevention machanism;

Forecasting methods;

Underground water handling approaches;

Fast TBM boring technology;

Long tunnel ventilation technology;

Rapid construction monitoring and feedback to direct dynamic design, etc.

3. Construction of Deep, Long & LargeTunnels and Safety of Tunnel Group

4. Optimized Joint Operation ofCascade Stations

Remote-controlled from the control center in Chengdu;

Benefit from joint operation begins to emerge;

An initial stage of joint operation achieved.


5. Environmental Benefits andEngineering Measures

Engineering measures taken concurrently with project construction;

Multi-level water-take structure for Jinping-I constructed to ensure proper temperature of the water released to the downstream of the river;

Jinping-II operated adopting usual criteria for the release of ecological flows ;

Jinping-Guandi Fish Hatchery in good operation.


Fish fry being released to the river


Hydropower development of the Yalong River is already in an expedited stage.

Key technical issues have been basically resolved.

An optimized pattern for joint operation of multiple stations is gradually taking shape.

Design and control of high earth-core rockfill dams will become the focus of further research.


Hydropower development of the Yalong River is already in an expedited stage.

Key technical issues have been basically resolved.

An optimized pattern for joint operation of multiple stations is gradually taking shape.

Design and control of high earth-core rockfill dams will become the focus of further research.


Thank you!

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KEY TECHNICAL ISSUES AND RESEARCH WORK IN YALONG …